Chuck device

ABSTRACT

To provide a chuck device for avoiding loosening of the fastened condition, in which an annular ratchet tooth wheel is provided in a body, an annular nut member that engages with the claws and rotates together with the rotary sleeve is provided inside the rotary sleeve and behind the ratchet wheel within the body, a retainer spring member that is composed of a leaf spring made of metal and detached and attached for engaging the ratchet tooth wheel is disposed outside of the ratchet tooth wheel, the retainer spring member is provided under the condition the retainer spring member is rotated around the ratchet wheel in accordance with a rotation of a retainer spring receiving sleeve within the retainer spring receiving sleeve that rotates together with the nut member and that is fitted around the nut member and made of metal, the retainer spring member is mounted on the retainer spring receiving sleeve by a convex/concave engagement means, a holder spring member that is composed of a metal made leaf spring formed as a detachable/attachable separate member from the retainer spring member for holding a retention release condition between the ratchet tooth wheel and the retainer spring member and the retention condition between the ratchet tooth wheel and the retainer spring member is disposed at a position facing the retainer spring member outside the ratchet tooth wheel, the holder spring member is adapted in the retainer spring receiving sleeve to rotate around the ratchet tooth wheel in accordance with the rotation of the retainer spring receiving sleeve, the holder spring member is mounted on the retainer spring receiving sleeve by the concave/convex engagement means, a metal made working sleeve that rotates together with the rotary sleeve and rotates through a predetermined angle relative to the retainer spring receiving sleeve is provided in the retainer spring receiving sleeve, a retainer working portion is provided in the working sleeve, the retainer working portion being composed of a retainer holder portion for maintaining a retention condition between the ratchet tooth wheel and the retainer spring member and a pressure portion for depressing the projection of the retainer spring member which is to be inserted into a hole portion of the retainer spring receiving sleeve and retaining the retainer spring member to the ratchet tooth wheel, a position holder portion for holding a position of the working sleeve to the retainer spring receiving sleeve to thereby hold the retention condition between the retainer spring member and the ratchet tooth wheel and the release condition between the retainer spring member and the ratchet tooth wheel is provided in the working sleeve, and the position holder portion is constituted by a projection of the holder spring member and a hole portion which is formed in the working sleeve and into which the projection is inserted, the projection is engaged with an elongated hole provided in the retainer spring receiving sleeve, the elongated hole has a tip end opening shape cut away from a tip end edge to a proximal end side of the retainer spring receiving sleeve so that the working sleeve may rotate within a range of the elongated hole to the retainer spring receiving sleeve and the nut member may rotate with the projection in contact with an inner end of the elongated hole, and the hole portion into which the projection of the retainer spring member is inserted has a tip end opening shape cut away from the tip end edge to the proximal end side of the retainer spring receiving sleeve.

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a chuck device for clamping atool.

[0002] Conventionally, chuck devices have been proposed.

[0003] These chuck devices are to be provided to an electric power tool.A predetermined tool such as a cutter blade (drill) is clamped by meansof the chuck device for drilling or the like.

[0004] By the way, a so-called hummer drill, a vibrating drill or thelike for good drilling work while imparting a shock or a vibration hasbeen used as the electric power tool.

[0005] This kind of the electric power tool is used for intermittentlyimparting a force (propelling force) in an axial direction. As a result,a twist force is likely to occur intermittently in the coupled tool sothat the tool is loosened.

SUMMARY OF THE INVENTION

[0006] An object of the present invention is to provide a chuck devicethat may solve the problems, and that is simple in structure andsuperior in durability.

[0007] In order to attain this and other objects, according to thepresent invention, there is provided a chuck device in which a chuckdevice in which a plurality of claws provided at a tip end of a body isslidingly opened and closed to clamp a tool with the claws by rotationof a rotary sleeve, wherein an annular ratchet tooth wheel is providedin the body, an annular nut member that engages with the claws androtates together with the rotary sleeve is provided inside the rotarysleeve and behind the ratchet wheel within the body, a retainer springmember that is composed of a leaf spring made of metal and detached andattached for engaging the ratchet tooth wheel is disposed outside of theratchet tooth wheel, the retainer spring member is provided under thecondition the retainer spring member is rotated around the ratchet wheelin accordance with a rotation of a retainer spring receiving sleevewithin the retainer spring receiving sleeve that rotates together withthe nut member and that is fitted around the nut member and made ofmetal, the retainer spring member is mounted on the retainer springreceiving sleeve by a convex/concave engagement means, a holder springmember that is composed of a metal made leaf spring formed as adetachable/attachable separate member from the retainer spring memberfor holding a retention release condition between the ratchet toothwheel and the retainer spring member and the retention condition betweenthe ratchet tooth wheel and the retainer spring member is disposed at aposition facing the retainer spring member outside the ratchet toothwheel, the holder spring member is adapted in the retainer springreceiving sleeve to rotate around the ratchet tooth wheel in accordancewith the rotation of the retainer spring receiving sleeve, the holderspring member is mounted on the retainer spring receiving sleeve by theconcave/convex engagement means, a metal made working sleeve thatrotates together with the rotary sleeve and rotates through apredetermined angle relative to the retainer spring receiving sleeve isprovided in the retainer spring receiving sleeve, a retainer workingportion is provided in the working sleeve, the retainer working portionbeing composed of a retainer holder portion for maintaining a retentioncondition between the ratchet tooth wheel and the retainer spring memberand a pressure portion for depressing the projection of the retainerspring member which is to be inserted into a hole portion of theretainer spring receiving sleeve and retaining the retainer springmember to the ratchet tooth wheel, a position holder portion for holdinga position of the working sleeve to the retainer spring receiving sleeveto thereby hold the retention condition between the retainer springmember and the ratchet tooth wheel and the release condition between theretainer spring member and the ratchet tooth wheel is provided in theworking sleeve, and the position holder portion is constituted by aprojection of the holder spring member and a hole portion which isformed in the working sleeve and into which the projection is inserted,the projection is engaged with an elongated hole provided in theretainer spring receiving sleeve, the elongated hole has a tip endopening shape cut away from a tip end edge to a proximal end side of theretainer spring receiving sleeve so that the working sleeve may rotatewithin a range of the elongated hole to the retainer spring receivingsleeve and the nut member may rotate with the projection in contact withan inner end of the elongated hole, and the hole portion into which theprojection of the retainer spring member is inserted has a tip endopening shape cut away from the tip end edge to the proximal end side ofthe retainer spring receiving sleeve.

[0008] According to the present invention, a chuck device in which aplurality of claws provided at a tip end of a body is slidingly openedand closed to clamp a tool with the claws by rotation of a rotarysleeve, is characterized in that an annular ratchet tooth wheel isprovided in the body, an annular nut member that engages with the clawsand rotates together with the rotary sleeve is provided inside therotary sleeve and behind the ratchet wheel within the body, a retainerspring member that is composed of a leaf spring made of metal anddetached and attached for engaging the ratchet tooth wheel is disposedoutside of the ratchet tooth wheel, the retainer spring member isprovided under the condition the retainer spring member is rotatedaround the ratchet wheel in accordance with a rotation of a retainerspring receiving sleeve within the retainer spring receiving sleeve thatrotates together with the nut member and that is fitted around the nutmember and made of metal, a structure in which a projection formed inthe retainer spring member is fitted in a hole portion formed in theretainer spring receiving sleeve is provided for mounting the retainerspring member onto the retainer spring receiving sleeve, a holder springmember that is composed of a metal made leaf spring formed as adetachable/attachable separate member from the retainer spring memberfor holding a retention release condition between the ratchet toothwheel and the retainer spring member and the retention condition betweenthe ratchet tooth wheel and the retainer spring member is disposed at aposition facing the retainer spring member outside the ratchet toothwheel, the holder spring member is adapted in the retainer springreceiving sleeve to rotate around the ratchet tooth wheel in accordancewith the rotation of the retainer spring receiving sleeve, the holderspring member is mounted on the retainer spring receiving sleeve by thestructure in which the projection formed in the retainer spring memberis fitted in the hole portion formed in the retainer spring receivingsleeve, a metal made working sleeve that rotates together with therotary sleeve and rotates through a predetermined angle relative to theretainer spring receiving sleeve is provided in the retainer springreceiving sleeve, a retainer working portion is provided in the workingsleeve, the retainer working portion being composed of a retainer holderportion for maintaining a retention condition between the ratchet toothwheel and the retainer spring member and a pressure portion fordepressing the projection of the retainer spring member which is to beinserted into a hole portion of the retainer spring receiving sleeve andretaining the retainer spring member to the ratchet tooth wheel, aposition holder portion for holding a position of the working sleeve tothe retainer spring receiving sleeve to thereby hold the retentioncondition between the retainer spring member and the ratchet tooth wheeland the release condition between the retainer spring member and theratchet tooth wheel is provided in the working sleeve, and the positionholder portion is constituted by a projection of the holder springmember and a hole portion which is formed in the working sleeve and intowhich the projection is inserted, the projection is engaged with anelongated hole provided in the retainer spring receiving sleeve, theelongated hole has a tip end opening shape cut away from a tip end edgeto a proximal end side of the retainer spring receiving sleeve so thatthe working sleeve may rotate within a range of the elongated hole tothe retainer spring receiving sleeve and the nut member may rotate withthe projection in contact with an inner end of the elongated hole, andthe hole portion provided in the retainer spring receiving sleeve has atip end opening shape cut away from the tip end edge to the proximal endside of the retainer spring receiving sleeve.

[0009] According to the invention, a chuck device in which a pluralityof claws provided at a tip end of a body is slidingly opened and closedto clamp a tool with the claws by rotation of a rotary sleeve, ischaracterized in that an annular ratchet tooth wheel is provided in thebody, an annular nut member that engages with the claws and rotatestogether with the rotary sleeve is provided inside the rotary sleeve andbehind the ratchet wheel within the body, a retainer spring member thatis composed of a leaf spring made of metal and detached and attached forengaging the ratchet tooth wheel is disposed outside of the ratchettooth wheel, the retainer spring member is provided under the conditionthe retainer spring member is rotated around the ratchet wheel inaccordance with a rotation of a retainer spring receiving sleeve withinthe retainer spring receiving sleeve that rotates together with the nutmember and that is fitted around the nut member and made of metal, astructure in which a projection and a hole portion formed in theretainer spring receiving sleeve and a recess portion and a projectionformed in the retainer spring member are engaged with each other isprovided for mounting the retainer spring member onto the retainerspring receiving sleeve, a holder spring member that is composed of ametal made leaf spring formed as a detachable/attachable separate memberfrom the retainer spring member for holding a retention releasecondition between the ratchet tooth wheel and the retainer spring memberand the retention condition between the ratchet tooth wheel and theretainer spring member is disposed at a position facing the retainerspring member outside the ratchet tooth wheel, the holder spring memberis adapted in the retainer spring receiving sleeve to rotate around theratchet tooth wheel in accordance with the rotation of the retainerspring receiving sleeve, the holder spring member is mounted on theretainer spring receiving sleeve by the structure in which theprojection and the hole portion formed in the retainer spring receivingsleeve and the recess portion and the projection formed in the retainerspring member are engaged with each other, a metal made working sleevethat rotates together with the rotary sleeve and rotates through apredetermined angle relative to the retainer spring receiving sleeve isprovided in the retainer spring receiving sleeve, a retainer workingportion is provided in the working sleeve, the retainer working portionbeing composed of a retainer holder portion for maintaining a retentioncondition between the ratchet tooth wheel and the retainer spring memberand a pressure portion for depressing the projection of the retainerspring member which is to be inserted into a hole portion of theretainer spring receiving sleeve and retaining the retainer springmember to the ratchet tooth wheel, a position holder portion for holdinga position of the working sleeve to the retainer spring receiving sleeveto thereby hold the retention condition between the retainer springmember and the ratchet tooth wheel and the release condition between theretainer spring member and the ratchet tooth wheel is provided in theworking sleeve, and the position holder portion is constituted by aprojection of the holder spring member and a hole portion which isformed in the working sleeve and into which the projection is inserted,the projection is engaged with an elongated hole provided in theretainer spring receiving sleeve, the elongated hole has a tip endopening shape cut away from a tip end edge to a proximal end side of theretainer spring receiving sleeve so that the working sleeve may rotatewithin a range of the elongated hole to the retainer spring receivingsleeve and the nut member may rotate with the projection in contact withan inner end of the elongated hole, and the hole portion provided in theretainer spring receiving sleeve has a tip end opening shape cut awayfrom the tip end edge to the proximal end side of the retainer springreceiving sleeve.

[0010] According to the present invention, a chuck device in which aplurality of claws provided at a tip end of a body is slidingly openedand closed to clamp a tool with the claws by rotation of a rotarysleeve, is characterized in that an annular ratchet tooth wheel isprovided in the body, an annular nut member that engages with the clawsand rotates together with the rotary sleeve is provided inside therotary sleeve and behind the ratchet wheel within the body, a retainerspring member that is composed of a leaf spring made of metal anddetached and attached for engaging the ratchet tooth wheel is disposedoutside of the ratchet tooth wheel, the retainer spring member isprovided under the condition the retainer spring member is rotatedaround the ratchet wheel in accordance with a rotation of a retainerspring receiving sleeve within the retainer spring receiving sleeve thatrotates together with the nut member and that is fitted around the nutmember and made of metal, the retainer spring member is mounted on theretainer spring receiving sleeve by a convex/concave engagement means, aholder spring member that is composed of a metal made leaf spring formedas a detachable/attachable separate member from the retainer springmember for holding a retention release condition between the ratchettooth wheel and the retainer spring member and the retention conditionbetween the ratchet tooth wheel and the retainer spring member isdisposed at a position facing the retainer spring member outside theratchet tooth wheel, the holder spring member is adapted in the retainerspring receiving sleeve to rotate around the ratchet tooth wheel inaccordance with the rotation of the retainer spring receiving sleeve,the holder spring member is mounted on the retainer spring receivingsleeve by the concave/convex engagement means, a metal made workingsleeve that rotates together with the rotary sleeve and rotates througha predetermined angle relative to the retainer spring receiving sleeveis provided in the retainer spring receiving sleeve, a retainer workingportion is provided in the working sleeve, the retainer working portionbeing composed of a retainer holder portion for maintaining a retentioncondition between the ratchet tooth wheel and the retainer spring memberand a retainer condition release portion for releasing the retainedcondition between the ratchet tooth wheel and the retainer springmember, a position holder portion for holding a position of the workingsleeve to the retainer spring receiving sleeve to thereby hold theretention condition between the retainer spring member and the ratchettooth wheel and the release condition between the retainer spring memberand the ratchet tooth wheel is provided in the working sleeve, and theposition holder portion is constituted by a projection of the holderspring member and a hole portion which is formed in the working sleeveand into which the projection is inserted, the projection is engagedwith an elongated hole provided in the retainer spring receiving sleeve,and the elongated hole has a tip end opening shape cut away from a tipend edge to a proximal end side of the retainer spring receiving sleeveso that the working sleeve may rotate within a range of the elongatedhole to the retainer spring receiving sleeve and the nut member mayrotate with the projection in contact with an inner end of the elongatedhole.

[0011] Also, in the chuck device, each component is made of metal.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a partially fragmentary, frontal view of a chuck deviceaccording to a first embodiment of the present invention.

[0013]FIG. 2 is an exploded perspective view of a primary part of thechuck device shown in FIG. 1.

[0014]FIG. 3 is a cross-sectional view taken along the line III-III ofFIG. 1.

[0015]FIG. 4 is a cross-sectional view taken along the line IV-IV ofFIG. 1.

[0016]FIG. 5 is a perspective view of a retainer spring member and aholder spring member in accordance with the first embodiment of thepresent invention.

[0017]FIG. 6 is an illustration showing a loosened phenomenon ofcoupling in an electric power tool according to this embodiment.

[0018]FIG. 7 is a partially fragmentary, frontal view of a chuck deviceaccording to a second embodiment of the present invention.

[0019]FIG. 8 is an exploded perspective view of a primary part of thechuck device shown in FIG. 7.

[0020]FIG. 9 is a cross-sectional view corresponding to FIG. 4 takenalong the line IX-IX of FIG. 7 according to the second embodiment of theinvention.

[0021]FIG. 10 is a cross-sectional view corresponding to FIG. 3 ofanother example that is a modification of a part of the firstembodiment.

[0022]FIG. 11 is a partially fragmentary, frontal view of a chuck deviceaccording to a third embodiment of the present invention.

[0023]FIG. 12 is an exploded perspective view of a primary part of thechuck device shown in FIG. 11.

[0024]FIG. 13 is a cross-sectional view corresponding to FIG. 3 takenalong the line XIII-XIII of FIG. 11 according to the third embodiment ofthe invention.

[0025]FIG. 14 is a cross-sectional view corresponding to FIG. 4 takenalong the line XIV-XIV of FIG. 11 according to the third embodiment ofthe invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] A first embodiment of the present invention will now be describedwith reference to FIGS. 1 to 5.

[0027] In this embodiment, the components are all made of metal.

[0028] Three claws 3 are slanted and provided in holes 2 a formed in abody 2. An annular nut member 6 that engages with a screw portion 3 aformed in an outer surface of the claws 3 is provided and engaged withthe claws 3. Incidentally, the nut member 6 is a split nut member 6 anda shape of the nut member 6 is maintained by a retainer spring receivingsleeve 8 to be described.

[0029] Also, an annular ratchet tooth wheel 5 is formed in front of thenut member 6 and in the body 2.

[0030] Reference numeral 13 denotes steel balls and numeral 14 denotessteel ball receivers.

[0031] The retainer spring receiving sleeve 8 that rotates together withthe nut member 6 is engaged with the nut member 6. Hole portions 8 a, 8b, 8 c and 8 d for mounting and rotating a retainer spring member 7 anda holder spring member 11 together with the spring retainer receivingsleeve 8 are provided in the retainer spring receiving sleeve 8. Sinceeach of these hole portions 8 a, 8 b, 8 c and 8 d has an open tip endcut away from a distal end edge to a proximal end side of the retainerspring receiving sleeve 8, it is possible to very easily perform theattachment/detachment of the retainer spring member 7 and the holderspring member 11 and it is possible to readily mount the retainer springmember 7 and the holder spring member 11 each of which has any desiredspring force.

[0032] The retainer spring member 7 and the holder spring member 11 aredisposed around the ratchet tooth wheel 5 to face each other. Also, inthe form shown in FIG. 5, i.e., in the retainer spring 7, twoprojections 7 a and 7 b and a tip end retainer portion 7′ for engagingwith the ratchet tooth wheel 5 are provided. On the other hand, twoprojections 11 c and 11 d are formed in the holder spring member 11. Theend portion associated with this projection 11 c is bent toward theprojection 11 d. When the projection 11 c is inserted into the holeportion 9 a, the bent portion is brought into pressing contact with theratchet tooth wheel 5 and exhibits the spring force as described later.The retainer spring member 7 is mounted so as to rotate together withthe retainer spring receiving sleeve 8 by the hole portions 8 a and 8 bof the above-described retainer spring receiving sleeve 8 and theprojections 7 a and 7 b of the retainer spring member 7. Also, theholder spring member 11 is mounted so as to rotate together with theretainer spring receiving sleeve 8 by the hole portions 8 c and 8 d ofthe above-described retainer spring receiving sleeve 8 and theprojections 11 c and 11 d of the holder spring member 11.

[0033] Incidentally, for the mounting manner of the projection portion 7a of the retainer spring member 7 and the projection portion 11 d of theholder spring member 11 on the retainer spring receiving sleeve 8, forexample, recess portions 7 a′ and 11 d′ may be provided instead of theprojection portion 7 a of the retainer spring member 7 and theprojection portion 11 d of the holder spring member 11 as shown in FIG.10, whereas projections 8 a′ and 8 d′ may be provided on the retainerspring receiving sleeve 8 for engaging the spring members with theretainer spring receiving sleeve. Namely, if the spring members and theretainer spring receiving sleeve may be rotated together, the mountingstructure is not limited to the above-described specific structure.

[0034] A working sleeve 9 received at its end in the body 2 is fitted inthe retainer spring receiving sleeve 8. The working sleeve 9 is rotatedtogether with the retainer spring receiving sleeve 8. However, when apredetermined load is applied to the rotation of the retainer springreceiving sleeve 8, the working sleeve 9 is adapted to rotate through apredetermined angle to the retainer spring receiving sleeve 8.

[0035] The rotation of the working sleeve 9 through the predeterminedangle to the retainer spring receiving sleeve 8 is attained by a simplestructure for inserting the projection 9 f inwardly projected and formedin the working sleeve 9 into the elongated hole 8 f formed in theretainer spring receiving sleeve 8 (i.e., the tip end opening structurein which the retainer spring receiving sleeve 8 is cut away from thedistal tip edge to the proximal end). Accordingly, it is also easy toassemble the working sleeve 9 with the retainer spring receiving sleeve8.

[0036] Also, since the working sleeve 9 is made separately from therotary sleeve 1 and made of metal, it is possible to form the projection9 f only by, for example, transfer press. Since the longitudinal hole 8f for receiving this projection 9 f is formed into the tip end openingshape cut away from the distal end edge to the proximal end side andformed with the same depth as that of the above-described hole portions8 a, 8 b, 8 c and 8 d, the projection 9 f may be arranged on the samecircumference as that of the retainer spring member 7 and the holderspring member 11. Accordingly, the retainer spring receiving sleeve 8may be formed short and compact. It is possible to obtain the torquetransmission structure that is superior in durability to the nut member6.

[0037] Reference numeral 9 c denotes a hole portion into which theprojection 11 c of the holder spring member 11 is inserted. Numeral 9 ddenotes a hole portion into which the projection 11 d of the holderspring member 11 is inserted. Numeral 9 b denotes a hole portion intowhich the projection 7 b of the retainer spring member 7 is inserted.Numeral 9 a denotes a hole portion into which the projection 7 a of theretainer spring member 7 is inserted.

[0038] Also, a pressure portion 10′ for depressing the projection 7 b ofthe retainer spring body 7 and a retainer holder portion 10″ (innersurface) for depressing the projection 7 b are formed in the workingsleeve 9. Furthermore, a pressure portion 12′ for depressing theprojection 11 c of the retainer spring member 11 is formed in theworking sleeve 9. Incidentally, since this pressure portion 10′ and theretainer holder portion 10″ are made of metal, the durable use thereofis possible.

[0039] A rotary sleeve 1 that rotates together with the working sleeve 9and is provided with a slippage preventing shape (serration) is fittedaround the working sleeve 9. The rotary sleeve 1 is received by astationary sleeve 15 that is fixed at a tip end to a stepped portion 2′of the body 2 and at a rear end to the body 2. Also, the projections 7 aand 7 b of the above-described retainer spring member 7 and theprojections 11 c and 11 d of the holder spring member 11 are received bythe inner surface of the rotary sleeve 1.

[0040] The structure in which the working member 9, the retainer springreceiving sleeve 8 and the nut member 6 are arranged inside the rotarysleeve 1 according to this embodiment has been thus described.

[0041] Incidentally, the stationary sleeve 15 may be made of syntheticresin. Also, it is possible to take a structure in which the rotarysleeve 1 is caused to extend to dispense with the stationary sleeve 15(in this case, the rotary sleeve 1 is supported to the receiving memberprovided in the body 2).

[0042] Reference numeral 16 denotes a C-shaped pull-off preventing ringfor the rotary sleeve 1, which is provided on the rear side of the tipend tapered portion of the body 2 and depressingly fitted in a recessgroove formed in the body 2. The rotary sleeve 1 is in sliding contactwith this pull-off preventing ring 16 and the tip end stepped portion 2′of the body 2. Accordingly, the back-and-forth movement of the rotarysleeve 1 is limited by this pull-off preventing ring 16 and the steppedportion 2′.

[0043] Reference numeral 17 denotes a receiving portion for receivingthe retainer spring member 7 and the holder spring member 11.

[0044] In operation, the chuck device according to the first embodimentof the present invention will work as follows. When the tool 4 isgripped by means of the claws 3 and the rotary sleeve 1 is rotated,until a predetermined load is applied to the rotary sleeve 1, the rotarysleeve 1, the working sleeve 9, the retainer spring receiving sleeve 8and the nut member 6 are rotated together. Accordingly, the holderspring body 11 and the retainer spring body 7 are also rotated aroundthe ratchet tooth wheel 5. When the rotary sleeve 1 is rotated to thepredetermined position (i.e., the position where the claws 3 are rotatedcorresponding to the tool 4), the predetermined load is applied to therotary sleeve 1 (in the condition of FIG. 3). When the rotary sleeve 1is further rotated from that condition, the working sleeve 9 is rotatedrelative to the retainer spring receiving sleeve 8 (within the range ofthe elongated hole 8 f). The pressure portion 10′ as the retainerworking portion 10 depresses the projection 7 b of the retainer springmember 7. The retainer holder portion 10″ as the retainer workingportion 10 receives the projection 7 b (under pressure). The tip endretainer portion 7′ of the retainer spring member 7 is brought intoabutment with the ratchet tooth wheel 5 with the projection 9 f beingbrought into abutment with the end portion of the elongated hole 8 f.The nut member 6 is rotated to increase the fastening force. The tip endretainer portion 7′ rides over the ratchet teeth of the wheel 5 one byone and retained at the predetermined ratchet tooth by the leaf springeffect (in the condition that the retainer portion is riding over theteeth one by one, the fastening operation has not yet been completed,and when the fastening operation has been finished, the riding-over ofthe teeth is stopped). Under this condition, the rotational resistanceof the rotary sleeve 1 is increased and the loosening of the coupling ofthe tool 4 is prevented by the spring force of the retainer springmember 7 (see FIG. 4). In this case, the pressure portion 12′ depressesthe projection 11 c of the holder spring retainer 11, and the projection11 c is inserted into the hole portion 9 a. Therefore, the engagementcondition between the ratchet tooth of the wheel 5 and the tip endretainer portion 7′ of the retainer spring member 7 is held without failby the engagement between the projection 11 c of the holder springmember 11 and the hole portion 9 a. The loosening of the coupling of thetool 4 is prevented as much as possible (in this sense, the positionholding portion 12 is constituted by the projection 11 c of the holderspring member 11 and the hole portions 9 c and 9 a of the working sleeve9).

[0045] Incidentally, the timing when the working sleeve 9 starts therotation relative to the retainer spring receiving sleeve 8 depends uponthe setup of the spring force of the holder spring member 11.

[0046] In order to release this coupled condition, when the rotarysleeve 1 is rotated in the reverse direction, the fastening of the tool4 is loosened by the opposite action to that described above.

[0047] By the way, as shown in FIG. 6, when the rotational direction ofthe body is in the direction indicated by arrows a, the propelling forceis applied intermittently in the axial direction so that a twist force(indicated by arrows in claws 32) intermittently occurs in the claw 32about the slant shaft 34 of the claw 32. The repeated twist force causesthe force for loosing (indicated by an arrow b in the nut member 35) tooccur in an engagement portion 33 between each claw 32 and a nut member35. As a result, the fastening of the tool 31 is loosened.

[0048] In particular, in case of this kind electric power rotary toolhaving a high drilling speed and a high power, naturally, the twistforce generated in the claws 32 is also large so that the fastening ofthe tool 31 is largely loosened.

[0049] Accordingly, U.S. Pat. No. 5,765,839 (hereinafter referred to asthe conventional example 1) discloses a chuck device having a structurefor preventing the loosening.

[0050] In the conventional example 1, after the tool has been fastened,the coupling of the tool is prevented from being loosened by a ratchetmechanism. However, this suffers from the following problem.

[0051] Namely, in the conventional example 1, since ratchet meansretained at a ratchet tooth for performing a ratchet function andretaining means for holding the current position of the ratchet meansare constituted by a single piece of leaf spring, for example, in thecase where the ratchet means has a high mechanical strength that isdurable against the stronger force, it is very difficult to realize sucha structure. As described above, in the case where the structure is usedin the high output electric power rotary tool, it is unnecessary tostrengthen the retaining means in conformity with the high outputelectric power rotary tool but it is sufficient to set the strength to apredetermined level. However, it is necessary to use the ratchet meansthat is strong in conformity with the output as described above. If theratchet means is strengthened for the high output electric power rotarytool, naturally, the retaining means is also to be strengthened becauseof the single piece leaf spring. Strengthening the retaining means wouldmean the very poor operationability. Incidentally, for instance, thereis an approach to prepare a leaf spring whose plate thickness ispartially changed. This is very troublesome and not practical.

[0052] Also, in the case where a strong leaf spring having a large platethickness is used as the spring for the high output electric powerrotary tool, the leaf spring is curved in an arcuate form and assembledinto the structure. This is also very troublesome.

[0053] Therefore, in order to solve this problem, for instance, U.S.Pat. No. 5,458,345 (hereinafter referred to as the conventional example2) proposes another approach.

[0054] In this conventional example 2, discrete members are used for theratchet means and the retaining means, respectively. However, thissystem also suffers from the following problem.

[0055] This conventional example 2 has a problem in durability becausethe retaining means is made of synthetic resin. Namely, since theretaining means is subjected to a thermal deformation (change in elasticconstant) by the heat generated during the drilling work and theretaining force is changed, the position of the above-described ratchetmeans is not suitable. Also, naturally, the retaining means made ofsynthetic resin is repetitively continuously used, resulting indegradation of a so-called elasticity. The example suffers from theproblem in this point.

[0056] Accordingly, the conventional example 2 may solve the probleminherent in the conventional example 1 by separating the ratchet meansand the retaining means but would be still insufficient due to theproblem of thermal deformation.

[0057] By the way, in the case where the electric rotary tool is lockedduring the working operation, a large twist force is applied to thetool, a twist is generated about the slant shaft 34 of the claw 32 andthe large force is left about the center of the engagement portions 33of the nut member 35. In this case, in order to release the engagementof the tool 31 in a reverse manner, a large loosening torque is neededto the rotary sleeve (the sleeve member for gripping to rotate the nutmember 35).

[0058] Therefore, in order to solve this point, for example, U.S. Pat.No. 5,829,761 (hereinafter referred to conventional example 3) has beenproposed. In this conventional example 3, for the purpose oftransmission of the torque from an outer sleeve (rotary sleeve) to aninner ring (nut member), a complicated structure is used inside of theouter sleeve. Accordingly, the soft material (resin) has to be usedinside the outer sleeve. Accordingly, the structure becomes a sandwichstructure of the outer sleeve, the soft material and the intermediatering. Accordingly, the outer sleeve is coupled with the intermediatering through the bypass. Correspondingly, the manufacture is difficult.Furthermore, the existence of the different material is not suitablealso in view of the current situation of the recycle for separation ofmaterial.

[0059] In view of the foregoing point, in the first embodiment, sincethe retainer spring member 7 and the holder spring member 11 areprovided separately from each other, for example, even if the retainerspring member 7 having the strong spring force is used for the highoutput electric power rotary tool, the spring force of the holder springmember 11 is not always increased unlike the conventional example 1.Accordingly, in spite that the loosening of the coupling hardly wouldtake place, it is possible to provide the chuck device that is superiorin operability and does not need any large force for releasing thelocked condition after the completion of the drilling work, for example.According to the first embodiment, it is possible to provide the chuckdevice in which any desired retainer spring member 7 and holder springbody 11 may be mounted for the characteristics of the electric powerrotary tool. The chuck device is thus superior in practical use.

[0060] Furthermore, according to the first embodiment, since all thecomponents including the holder spring member 11 are made of metal, thedeformation due to the heat generated together with the drilling work asin the conventional example 2 (change in elastic constant) may beprevented as much as possible. Correspondingly, it is possible toprovide the chucking device in which the coupling hardly would beloosened and that is durable for the repetitive continuous use.

[0061] Accordingly, it is possible to provide the chuck device in whichthe loosening of the coupling of the tool 4 may be prevented withoutfail and which is superior in recycle characteristics and in durabilitywith the simple structure.

[0062] FIGS. 7 to 9 show a second embodiment of the present invention.This will now be described.

[0063] In the second embodiment, the working sleeve 9 is bent at tip endto form a projection 9 f′ (corresponding to the projection 9 f of thefirst embodiment).

[0064] In the working sleeve 9 of the second embodiment, several slits18 are provided close to the proximal end thereof. Projecting pieces 19′of a snap ring 19 are inserted into the slits 18. Accordingly, theworking sleeve 9 is retained at the body 2 by means of the snap ring 19.As a result, the forward movement of the rotary sleeve 1 is limited bymeans of the working sleeve 9 and the rearward movement is limited bymeans of the above-described stepped portion 2′.

[0065] The other structure is the same as that of the first embodiment.

[0066] FIGS. 11 to 14 show a third embodiment of the present invention.This will now be described.

[0067] The third embodiment is different from the first embodiment andthe second embodiment in movement of the retainer spring member 7.

[0068] Namely, when the tool 4 is coupled, the rotary sleeve 1 isrotated and the predetermined load is applied to the rotary sleeve 1,the working sleeve 9 is rotated to the retainer spring receiving sleeve8, so that the retainer condition release portion 20″ (a piece formed bybending the working sleeve 9) provided in the working sleeve 9 is movedfrom the condition of FIG. 13 to the condition of FIG. 14. The tip endretainer portion 7′ of the retainer spring member 7 that is separatedfrom the ratchet tooth wheel 5 by means of this piece is retained at theratchet tooth wheel 5 by its elasticity. This condition is maintained bya retainer holding portion 20′ (an inner surface of the working sleeve9).

[0069] The other is the same as that of the first embodiment and thesecond embodiment.

[0070] As described above, the first embodiment, the second embodimentand the third embodiment are different from each other in structure formounting the retainer spring member 7 and the holder spring member 11 onthe retainer spring receiving sleeve 8, the structure (shape) of themember moving within the elongated hole 8 f of the retainer springreceiving sleeve 8, and the structure for releasing and engaging betweenthe retainer spring member 7 and the ratchet tooth wheel 5. It ispossible to use any other structure other than the combination shown.

What is claimed is:
 1. A chuck device in which a plurality of clawsprovided at a tip end of a body is slidingly opened and closed to clampa tool with the claws by rotation of a rotary sleeve, wherein an annularratchet tooth wheel is provided in the body, an annular nut member thatengages with said claws and rotates together with said rotary sleeve isprovided inside the rotary sleeve and behind the ratchet wheel withinthe body, a retainer spring member that is composed of a leaf springmade of metal and detached and attached for engaging said ratchet toothwheel is disposed outside of said ratchet tooth wheel, said retainerspring member is provided under the condition said retainer springmember is rotated around the ratchet wheel in accordance with a rotationof a retainer spring receiving sleeve within said retainer springreceiving sleeve that rotates together with said nut member and that isfitted around said nut member and made of metal, said retainer springmember is mounted on the retainer spring receiving sleeve by aconvex/concave engagement means, a holder spring member that is composedof a metal made leaf spring formed as a detachable/attachable separatemember from said retainer spring member for holding a retention releasecondition between said ratchet tooth wheel and said retainer springmember and the retention condition between the ratchet tooth wheel andsaid retainer spring member is disposed at a position facing saidretainer spring member outside said ratchet tooth wheel, said holderspring member is adapted in said retainer spring receiving sleeve torotate around the ratchet tooth wheel in accordance with the rotation ofsaid retainer spring receiving sleeve, said holder spring member ismounted on the retainer spring receiving sleeve by said concave/convexengagement means, a metal made working sleeve that rotates together withsaid rotary sleeve and rotates through a predetermined angle relative tosaid retainer spring receiving sleeve is provided in said retainerspring receiving sleeve, a retainer working portion is provided in saidworking sleeve, said retainer working portion being composed of aretainer holder portion for maintaining a retention condition betweensaid ratchet tooth wheel and said retainer spring member and a pressureportion for depressing the projection of said retainer spring memberwhich is to be inserted into a hole portion of said retainer springreceiving sleeve and retaining said retainer spring member to saidratchet tooth wheel, a position holder portion for holding a position ofsaid working sleeve to said retainer spring receiving sleeve to therebyhold the retention condition between said retainer spring member andsaid ratchet tooth wheel and the release condition between said retainerspring member and said ratchet tooth wheel is provided in said workingsleeve, and said position holder portion is constituted by a projectionof said holder spring member and a hole portion which is formed in saidworking sleeve and into which said projection is inserted, saidprojection is engaged with an elongated hole provided in said retainerspring receiving sleeve, said elongated hole has a tip end opening shapecut away from a tip end edge to a proximal end side of said retainerspring receiving sleeve so that said working sleeve may rotate within arange of said elongated hole to said retainer spring receiving sleeveand said nut member may rotate with said projection in contact with aninner end of said elongated hole, and said hole portion into which saidprojection of said retainer spring member is inserted has a tip endopening shape cut away from the tip end edge to the proximal end side ofsaid retainer spring receiving sleeve.
 2. A chuck device in which aplurality of claws provided at a tip end of a body is slidingly openedand closed to clamp a tool with the claws by rotation of a rotarysleeve, wherein an annular ratchet tooth wheel is provided in the body,an annular nut member that engages with said claws and rotates togetherwith said rotary sleeve is provided inside the rotary sleeve and behindthe ratchet wheel within the body, a retainer spring member that iscomposed of a leaf spring made of metal and detached and attached forengaging said ratchet tooth wheel is disposed outside of said ratchettooth wheel, said retainer spring member is provided under the conditionsaid retainer spring member is rotated around the ratchet wheel inaccordance with a rotation of a retainer spring receiving sleeve withinsaid retainer spring receiving sleeve that rotates together with saidnut member and that is fitted around said nut member and made of metal,a structure in which a projection formed in said retainer spring memberis fitted in a hole portion formed in said retainer spring receivingsleeve is provided for mounting said retainer spring member onto saidretainer spring receiving sleeve, a holder spring member that iscomposed of a metal made leaf spring formed as a detachable/attachableseparate member from said retainer spring member for holding a retentionrelease condition between said ratchet tooth wheel and said retainerspring member and the retention condition between the ratchet toothwheel and said retainer spring member is disposed at a position facingsaid retainer spring member outside said ratchet tooth wheel, saidholder spring member is adapted in said retainer spring receiving sleeveto rotate around the ratchet tooth wheel in accordance with the rotationof said retainer spring receiving sleeve, said holder spring member ismounted on the retainer spring receiving sleeve by said structure inwhich the projection formed in said retainer spring member is fitted inthe hole portion formed in said retainer spring receiving sleeve, ametal made working sleeve that rotates together with said rotary sleeveand rotates through a predetermined angle relative to said retainerspring receiving sleeve is provided in said retainer spring receivingsleeve, a retainer working portion is provided in said working sleeve,said retainer working portion being composed of a retainer holderportion for maintaining a retention condition between said ratchet toothwheel and said retainer spring member and a pressure portion fordepressing the projection of said retainer spring member which is to beinserted into a hole portion of said retainer spring receiving sleeveand retaining said retainer spring member to said ratchet tooth wheel, aposition holder portion for holding a position of said working sleeve tosaid retainer spring receiving sleeve to thereby hold the retentioncondition between said retainer spring member and said ratchet toothwheel and the release condition between said retainer spring member andsaid ratchet tooth wheel is provided in said working sleeve, and saidposition holder portion is constituted by a projection of said holderspring member and a hole portion which is formed in said working sleeveand into which said projection is inserted, said projection is engagedwith an elongated hole provided in said retainer spring receivingsleeve, said elongated hole has a tip end opening shape cut away from atip end edge to a proximal end side of said retainer spring receivingsleeve so that said working sleeve may rotate within a range of saidelongated hole to said retainer spring receiving sleeve and said nutmember may rotate with said projection in contact with an inner end ofsaid elongated hole, and said hole portion provided in said retainerspring receiving sleeve has a tip end opening shape cut away from thetip end edge to the proximal end side of said retainer spring receivingsleeve.
 3. A chuck device in which a plurality of claws provided at atip end of a body is slidingly opened and closed to clamp a tool withthe claws by rotation of a rotary sleeve, wherein an annular ratchettooth wheel is provided in the body, an annular nut member that engageswith said claws and rotates together with said rotary sleeve is providedinside the rotary sleeve and behind the ratchet wheel within the body, aretainer spring member that is composed of a leaf spring made of metaland detached and attached for engaging said ratchet tooth wheel isdisposed outside of said ratchet tooth wheel, said retainer springmember is provided under the condition said retainer spring member isrotated around the ratchet wheel in accordance with a rotation of aretainer spring receiving sleeve within said retainer spring receivingsleeve that rotates together with said nut member and that is fittedaround said nut member and made of metal, a structure in which aprojection and a hole portion formed in said retainer spring receivingsleeve and a recess portion and a projection formed in said retainerspring member are engaged with each other is provided for mounting saidretainer spring member onto said retainer spring receiving sleeve, aholder spring member that is composed of a metal made leaf spring formedas a detachable/attachable separate member from said retainer springmember for holding a retention release condition between said ratchettooth wheel and said retainer spring member and the retention conditionbetween the ratchet tooth wheel and said retainer spring member isdisposed at a position facing said retainer spring member outside saidratchet tooth wheel, said holder spring member is adapted in saidretainer spring receiving sleeve to rotate around the ratchet toothwheel in accordance with the rotation of said retainer spring receivingsleeve, said holder spring member is mounted on the retainer springreceiving sleeve by said structure in which the projection and the holeportion formed in said retainer spring receiving sleeve and the recessportion and the projection formed in said retainer spring member areengaged with each other, a metal made working sleeve that rotatestogether with said rotary sleeve and rotates through a predeterminedangle relative to said retainer spring receiving sleeve is provided insaid retainer spring receiving sleeve, a retainer working portion isprovided in said working sleeve, said retainer working portion beingcomposed of a retainer holder portion for maintaining a retentioncondition between said ratchet tooth wheel and said retainer springmember and a pressure portion for depressing the projection of saidretainer spring member which is to be inserted into a hole portion ofsaid retainer spring receiving sleeve and retaining said retainer springmember to said ratchet tooth wheel, a position holder portion forholding a position of said working sleeve to said retainer springreceiving sleeve to thereby hold the retention condition between saidretainer spring member and said ratchet tooth wheel and the releasecondition between said retainer spring member and said ratchet toothwheel is provided in said working sleeve, and said position holderportion is constituted by a projection of said holder spring member anda hole portion which is formed in said working sleeve and into whichsaid projection is inserted, said projection is engaged with anelongated hole provided in said retainer spring receiving sleeve, saidelongated hole has a tip end opening shape cut away from a tip end edgeto a proximal end side of said retainer spring receiving sleeve so thatsaid working sleeve may rotate within a range of said elongated hole tosaid retainer spring receiving sleeve and said nut member may rotatewith said projection in contact with an inner end of said elongatedhole, and said hole portion provided in said retainer spring receivingsleeve has a tip end opening shape cut away from the tip end edge to theproximal end side of said retainer spring receiving sleeve.
 4. A chuckdevice in which a plurality of claws provided at a tip end of a body isslidingly opened and closed to clamp a tool with the claws by rotationof a rotary sleeve, wherein an annular ratchet tooth wheel is providedin the body, an annular nut member that engages with said claws androtates together with said rotary sleeve is provided inside the rotarysleeve and behind the ratchet wheel within the body, a retainer springmember that is composed of a leaf spring made of metal and detached andattached for engaging said ratchet tooth wheel is disposed outside ofsaid ratchet tooth wheel, said retainer spring member is provided underthe condition said retainer spring member is rotated around the ratchetwheel in accordance with a rotation of a retainer spring receivingsleeve within said retainer spring receiving sleeve that rotatestogether with said nut member and that is fitted around said nut memberand made of metal, said retainer spring member is mounted on theretainer spring receiving sleeve by a convex/concave engagement means, aholder spring member that is composed of a metal made leaf spring formedas a detachable/attachable separate member from said retainer springmember for holding a retention release condition between said ratchettooth wheel and said retainer spring member and the retention conditionbetween the ratchet tooth wheel and said retainer spring member isdisposed at a position facing said retainer spring member outside saidratchet tooth wheel, said holder spring member is adapted in saidretainer spring receiving sleeve to rotate around the ratchet toothwheel in accordance with the rotation of said retainer spring receivingsleeve, said holder spring member is mounted on the retainer springreceiving sleeve by said concave/convex engagement means, a metal madeworking sleeve that rotates together with said rotary sleeve and rotatesthrough a predetermined angle relative to said retainer spring receivingsleeve is provided in said retainer spring receiving sleeve, a retainerworking portion is provided in said working sleeve, said retainerworking portion being composed of a retainer holder portion formaintaining a retention condition between said retainer spring memberand said ratchet tooth wheel and a retainer condition release portionfor releasing the retained condition between said retainer spring memberand said ratchet tooth wheel, a position holder portion for holding aposition of said working sleeve to said retainer spring receiving sleeveto thereby hold the retention condition between said retainer springmember and said ratchet tooth wheel and the release condition betweensaid retainer spring member and said ratchet tooth wheel is provided insaid working sleeve, and said position holder portion is constituted bya projection of said holder spring member and a hole portion which isformed in said working sleeve and into which said projection isinserted, and said projection is engaged with an elongated hole providedin said retainer spring receiving sleeve, and said elongated hole has atip end opening shape cut away from a tip end edge to a proximal endside of said retainer spring receiving sleeve so that said workingsleeve may rotate within a range of said elongated hole to said retainerspring receiving sleeve and said nut member may rotate with saidprojection in contact with an inner end of said elongated hole.
 5. Thechuck device according to any one of claims 1 to 4, wherein eachcomponent is made of metal.